1. Field of the Invention
The present invention relates to a fixing device mounted to image forming apparatuses such as coping machines, printers, facsimile machines and, more specifically, to a fixing device for an image forming apparatus in which an induction heating system is employed.
2. Description of Background
In recent years, there exists a fixing device used for image forming apparatuses such as electrophotographic copying machines and printers, in which an induction heating system is employed. The fixing devices employing the induction heating system as such include a device in which speeding up of the fixing speed is realized by further increasing the warming up speed of the fixing device. For example, an Image Device in which the warming up time is reduced by arranging an exciting coil around a heat-generating roller is disclosed in U.S. Pat. No. 6,819,904.
However, in the device in the related art described above, although the speeding up is realized by heating the heat-generating roller provided on the side which comes into contact with a toner image by the exciting coil, there is no heat source on the side of a pressurizing member. Therefore, when a large amount of heat is consumed continuously as in a case of fixing color images consecutively at a high speed, the amount of heat is not sufficient especially on the side of the pressurizing member, and there is a fear that defective quality of fixing image occurs.
Therefore, in the fixing device in which the speeding up is realized by the induction heating system, the development of a fixing device for an image forming apparatus, in which the shortage of the amount of heat on the side of the pressurizing member is solved so that a high quality fixed image is obtained without defective quality of fixing image even in the case of forming color images consecutively at a high speed, is desired.